Semi-closed power generation circulation system and isothermal variable load method thereof

Abstract

The embodiment of the invention provides a semi-closed type power generation circulation system and an isothermal variable load method thereof. The semi-closed type power generation circulation system comprises a combustor, a gas turbine connected to a power generator, a heat regenerator, a circulation assembly, a first adjusting valve and a second adjusting valve. A flue gas outlet of the combustor is communicated with an inlet of the gas turbine, an outlet of the gas turbine is communicated with a hot side inlet of the heat regenerator, and a cold side outlet of the heat regenerator is communicated with a flue gas inlet of the combustor; the circulating assembly communicates with a hot side outlet and a cold side inlet of the heat regenerator, a first adjusting valve is connected between a smoke outlet of the combustor and an inlet of the gas turbine in series, and a second adjusting valve is connected between the smoke outlet of the combustor and the hot side inlet of the heat regenerator in series. According to the semi-closed power generation circulation system and the isothermal load change method thereof, the load change rate of the power generation circulation system can be improved, and the peak regulation requirement of a thermal power generating unit can be better met.

Description

Technical Field

[0001] The embodiments of the present disclosure belong to the technical field of semi-closed cycle power generation, and specifically relate to a semi-closed power generation cycle system and an isothermal variable load method thereof. Background Art

[0002] my country is currently vigorously developing a variety of renewable energy sources, including wind power and photovoltaics. Renewable energy generation is carbon-free or contains minimal carbon, resulting in minimal environmental impact and playing a significant role in promoting the transformation of my country's energy structure. Due to the inherent intermittent and volatile nature of renewable energy, the absorption of renewable energy power places higher demands on existing thermal power units, requiring them to possess greater flexibility. However, due to limitations in pulverized coal combustion, heat transfer, and equipment, the peak-shaving rate of coal-fired power generation units can only reach 2.5%Pe / min-4%Pe / min, which is insufficient to meet peak-shaving requirements.

[0003] The semi-closed power generation cycle system in the relevant technology can solve the flexibility and other problems of existing coal-fired power generation units to a certain extent. However, during the load change process, the combustion conditions, equipment and pipeline temperatures, pipeline pressure, etc. fluctuate greatly, which can easily cause fatigue of metal materials, thereby affecting the life of the unit and, to a certain extent, affecting the stable operation of the semi-closed power generation cycle system. Summary of the Invention

[0004] The embodiments of the present disclosure aim to solve at least one of the technical problems existing in the prior art and provide a semi-closed power generation cycle system and an isothermal load-changing method thereof.

[0005] In one aspect, an embodiment of the present disclosure provides a semi-closed power generation cycle system, the semi-closed power generation cycle system comprising a burner, a gas turbine connected to a generator, a regenerator, a cycle component, a first regulating valve, and a second regulating valve;

[0006] The flue gas outlet of the burner is communicated with the inlet of the gas turbine, the outlet of the gas turbine is communicated with the hot side inlet of the regenerator, and the cold side outlet of the regenerator is communicated with the flue gas inlet of the burner; and,

[0007] The circulation component is connected to the hot side outlet and the cold side inlet of the regenerator respectively. The first regulating valve is connected in series between the flue gas outlet of the burner and the inlet of the gas turbine, and the second regulating valve is connected in series between the flue gas outlet of the burner and the hot side inlet of the regenerator.

[0008] Optionally, the generator and the gas turbine are linked via a coupling, and the burner further has a receiving port for receiving combustion raw materials to burn and generate hot flue gas.

[0009] Optionally, the circulation component includes a cooler, a gas-liquid separator, and a compressor connected to an electric motor;

[0010] The inlet and outlet of the cooler are respectively connected to the hot side outlet of the regenerator and the inlet of the gas-liquid separator;

[0011] The inlet and outlet of the compressor are respectively communicated with the gas outlet of the gas-liquid separator and the cold side inlet of the regenerator, and the liquid outlet of the gas-liquid separator is used to discharge condensed water.

[0012] Optionally, the circulation component further comprises a precooler and a pressure stabilizing tank connected in series between the gas-liquid separator and the compressor;

[0013] The inlet and outlet of the precooler are respectively communicated with the gas outlet of the gas-liquid separator and the inlet of the surge tank, and the first outlet of the surge tank is communicated with the inlet of the compressor.

[0014] Optionally, the electric motor and the compressor are linked via a coupling, and the second outlet of the surge tank is used to discharge gas for gas capture.

[0015] Optionally, the first outlet and the second outlet are located at the top and bottom of the surge tank respectively.

[0016] Optionally, the flue gas outlet of the burner is connected to the inlet of the gas turbine via a first pipe, and the flue gas outlet of the burner is connected to the hot side inlet of the regenerator via a second pipe;

[0017] The first regulating valve is connected in series to the first pipeline, and the second regulating valve is connected in series to the second pipeline.

[0018] Optionally, the valve nominal diameter of the second regulating valve is half of the valve nominal diameter of the first regulating valve, and the pipe nominal diameter of the second pipeline is half of the pipe nominal diameter of the first pipeline.

[0019] On the other hand, an embodiment of the present disclosure provides an isothermal load-variable method for a semi-closed power generation cycle system, using the aforementioned semi-closed power generation cycle system, the method comprising:

[0020] When the load needs to be reduced, the first regulating valve is closed and the second regulating valve is opened synchronously; when the load needs to be increased, the first regulating valve is opened and the second regulating valve is closed synchronously; wherein,

[0021] When the first regulating valve is in a fully open state and the second regulating valve is in a fully closed state, the semi-closed power generation cycle system is in a full-load operating state.

[0022] The semi-closed power generation cycle system and isothermal load variation method of the embodiments disclosed herein, through the provided burner, the gas turbine connected to the generator, the regenerator, the circulation component, the first regulating valve and the second regulating valve, can achieve isothermal load variation by adjusting the opening of the first regulating valve and the second regulating valve without adjusting the combustion conditions of the burner. Parameters such as the temperature and pressure at various positions in the circulation system remain almost unchanged. Under the condition of small-scale load variation, the use of this circulation system can minimize the impact of temperature and pressure changes caused by load variation on various equipment and pipelines of the thermal power unit, thereby reducing fatigue of metal components. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a structural schematic diagram of a semi-closed power generation cycle system according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to better understand the technical solutions of the present disclosure, the present disclosure is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0025] like Figure 1 As shown, a semi-closed power generation cycle system 100 includes a burner 110, a gas turbine 120 connected to a generator 200, a regenerator 130, a circulation assembly 140, a first regulating valve 150, and a second regulating valve 160. The flue gas outlet of the burner 110 is connected to the inlet of the gas turbine 120, the outlet of the gas turbine 120 is connected to the hot side inlet of the regenerator 130, and the cold side outlet of the regenerator 130 is connected to the flue gas inlet of the burner 110.

[0026] The circulation component 140 is connected to the hot side outlet and the cold side inlet of the regenerator 130 respectively. The first regulating valve 150 is connected in series between the flue gas outlet of the burner 110 and the inlet of the gas turbine 120. The second regulating valve 160 is connected in series between the flue gas outlet of the burner 110 and the hot side inlet of the regenerator 130.

[0027] Specifically, if Figure 1As shown, the burner 110 has a receiving port for receiving combustion materials to burn and generate hot flue gas. The combustion materials include fuel gas and oxygen. The main components of fuel gas are hydrogen and carbon monoxide or methane. They enter the burner 110 together with oxygen. The hot flue gas after combustion mainly consists of water vapor and carbon dioxide. The hot flue gas enters the gas turbine 120, driving the blades in the gas turbine 120 to rotate and perform work. The flue gas after performing work enters the hot side of the regenerator 130, and the heat is used to heat the circulating working medium. The cooled flue gas enters the circulation component 140, and after being processed by the circulation component 140, it enters the cold side of the regenerator 130 again. After being heated, it enters the burner 110, forming a cycle.

[0028] The generator 200 and the gas turbine 120 are linked via a coupling, and the gas turbine 120 drives the generator 200 to rotate and generate electricity via the coupling.

[0029] When the thermal power unit is operating normally at full load, the first regulating valve 150 is fully open and the second regulating valve 160 does not participate in the operation. When isothermal load variation is required, the second regulating valve 160 gradually adjusts its opening to participate in isothermal load variation regulation. As an example, Figure 1 As shown, the flue gas outlet of the burner 110 is connected to the inlet of the gas turbine 120 via a first pipe 400, and the flue gas outlet of the burner 110 is connected to the hot side inlet of the regenerator 130 via a second pipe 500. The first regulating valve 150 is connected in series to the first pipe 400, and the second regulating valve 160 is connected in series to the second pipe 500.

[0030] Furthermore, the valve nominal diameter of the second regulating valve 160 is half the valve nominal diameter of the first regulating valve 150 , and the pipe nominal diameter of the second pipeline 500 is half the pipe nominal diameter of the first pipeline 400 .

[0031] To reduce the load, the second regulating valve 160 is gradually opened, while the opening of the first regulating valve 150 is simultaneously reduced. This causes a portion of the hot flue gas from the burner 110 to no longer flow through the gas turbine 120, but instead enter the hot side of the regenerator 130. This reduces the amount of hot flue gas flowing through the gas turbine 120, lowering the output of the gas turbine 120 and achieving load reduction. When the opening of the second regulating valve 160 is approximately 20%-30%, approximately 20% of the hot flue gas flows through the second pipeline 500 and 80% of the hot flue gas flows through the gas turbine 120. The opening of the first regulating valve 150 is simultaneously adjusted to approximately 80%, reducing the output of the gas turbine 120 to 80% of full load. To increase the load, the second regulating valve 160 is gradually closed, while the opening of the first regulating valve 150 is simultaneously increased. This gradually increases the amount of hot flue gas flowing through the gas turbine 120, increasing the output of the gas turbine 120 and achieving load increase. When the second regulating valve 160 is fully closed and the first regulating valve 150 is fully open, the output of the gas turbine 120 returns to full load. During this load reduction and load increase process, the combustion conditions of the burner 110, including parameters such as the fuel quantity, combustion temperature and pressure, the speed of the compressor 143, and the temperature and pressure at various locations in the circulation system 100, remain largely unchanged.

[0032] It should be noted that the ratio of the valve nominal diameter of the second regulating valve 160 to the valve nominal diameter of the first regulating valve 150, the regulating valve types of the two, and the nominal diameters of the first pipeline 400 and the second pipeline 500 can all be adjusted according to actual needs, and the embodiments of the present disclosure do not impose specific restrictions on this.

[0033] For example, Figure 1 As shown, the circulation component 140 includes a cooler 141, a gas-liquid separator 142, and a compressor 143 connected to the motor 300. The inlet and outlet of the cooler 141 are respectively connected to the hot side outlet of the regenerator 130 and the inlet of the gas-liquid separator 142. The inlet and outlet of the compressor 143 are respectively connected to the gas outlet of the gas-liquid separator 142 and the cold side inlet of the regenerator 130. The liquid outlet of the gas-liquid separator 142 is used to discharge condensed water.

[0034] Furthermore, the circulation component 140 further includes a precooler 144 and a surge tank 145 connected in series between the gas-liquid separator 142 and the compressor 143. The inlet and outlet of the precooler 144 are respectively connected to the gas outlet of the gas-liquid separator 142 and the inlet of the surge tank 145, and the first outlet of the surge tank 145 is connected to the inlet of the compressor 143.

[0035] Specifically, if Figure 1As shown, burner 110 generates hot flue gas that enters gas turbine 120, driving the blades in gas turbine 120 to rotate and produce work. The flue gas, after performing work, enters the hot side of regenerator 130, where the heat is used to heat the circulating working fluid. The cooled flue gas enters cooler 141, where water vapor in the flue gas condenses into water. The cooled flue gas and water enter gas-liquid separator 142. The flue gas, primarily composed of carbon dioxide, enters precooler 144 for further cooling before entering surge tank 145 and compressor 143. The pressurized flue gas enters the cold side of regenerator 130, where it is heated before entering burner 110, completing the cycle.

[0036] The liquid outlet of the gas-liquid separator 142 is used to discharge condensed water, and the liquid outlet is provided at the bottom of the gas-liquid separator 142. The main component of the flue gas in the surge tank 145 is carbon dioxide, a part of which is discharged from the second outlet of the surge tank 145 for gas capture (carbon capture), and the other part enters the compressor 143 for pressurized circulation. The motor 300 and the compressor 143 are linked by a coupling, and the motor 300 drags the compressor 143 through the coupling to rotate and perform work, thereby compressing carbon dioxide. The two regulating valves are adjusted together to change the ratio of hot flue gas flowing through the gas turbine, thereby changing the output of the gas turbine. At the same time, the parameters such as the burner combustion conditions, the compressor speed, the temperature and pressure at each position of the circulation system remain almost unchanged, realizing the isothermal variable load of the semi-closed power generation cycle system.

[0037] In the semi-closed power generation cycle system of the disclosed embodiment, when load reduction is required during operation, the second regulating valve 160 is gradually opened while the opening of the first regulating valve 150 is simultaneously reduced. As a result, a portion of the hot flue gas from the burner 110 no longer flows through the gas turbine 120 but directly enters the hot side of the regenerator 130. This reduces the amount of hot flue gas flowing through the gas turbine 120, lowering the output of the gas turbine 120 and achieving load reduction. When load increase is required, the second regulating valve 160 is gradually closed while the opening of the first regulating valve 150 is simultaneously increased. This gradually increases the amount of hot flue gas flowing through the gas turbine 120 and increases the output of the gas turbine 120, achieving load increase. Without adjusting the combustion conditions of the burner 110 and the speed of the compressor 143, isothermal load variation is achieved by adjusting the openings of the first regulating valve 150 and the second regulating valve 160. Parameters such as the temperature and pressure at various positions in the circulation system remain almost unchanged. Under the condition of small-scale load variation, the use of this circulation system can minimize the impact of temperature and pressure changes on various equipment and pipelines of the thermal power unit caused by variable loads, thereby reducing fatigue of metal components.

[0038] For example, the first outlet and the second outlet are respectively located at the top and bottom of the surge tank 145. This arrangement can more conveniently divide and realize that part of the carbon dioxide enters the compressor for pressurization circulation and the other part is discharged for carbon capture.

[0039] In another aspect, embodiments of the present disclosure provide an isothermal load-variable method for a semi-closed power generation cycle system. Using the aforementioned semi-closed power generation cycle system, the method includes closing a first regulating valve and simultaneously opening a second regulating valve when load reduction is required. When load increase is required, opening the first regulating valve and simultaneously closing the second regulating valve. When the first regulating valve is fully open and the second regulating valve is fully closed, the semi-closed power generation cycle system is operating at full load.

[0040] It is understood that the above embodiments are merely exemplary embodiments for illustrating the principles of the present disclosure, and the present disclosure is not limited thereto. Those skilled in the art may make various modifications and improvements without departing from the spirit and substance of the present disclosure, and such modifications and improvements are also considered to be within the scope of protection of the present disclosure.

Claims

1. A semi-closed power generation cycle system, characterized in that: The semi-closed power generation cycle system includes a burner, a gas turbine connected to a generator, a regenerator, a circulation component, a first regulating valve and a second regulating valve; The flue gas outlet of the burner is communicated with the inlet of the gas turbine, the outlet of the gas turbine is communicated with the hot side inlet of the regenerator, and the cold side outlet of the regenerator is communicated with the flue gas inlet of the burner; and, The circulation component is connected to the hot side outlet and the cold side inlet of the regenerator respectively. The first regulating valve is connected in series between the flue gas outlet of the burner and the inlet of the gas turbine, and the second regulating valve is connected in series between the flue gas outlet of the burner and the hot side inlet of the regenerator.

2. The semi-closed power generation cycle system according to claim 1, characterized in that: The generator and the gas turbine are linked via a coupling, and the burner also has a material receiving port for receiving combustion raw materials to burn and generate hot flue gas.

3. The semi-closed power generation cycle system according to claim 1, characterized in that: The circulation component includes a cooler, a gas-liquid separator and a compressor connected to the motor; The inlet and outlet of the cooler are respectively connected to the hot side outlet of the regenerator and the inlet of the gas-liquid separator; The inlet and outlet of the compressor are respectively communicated with the gas outlet of the gas-liquid separator and the cold side inlet of the regenerator, and the liquid outlet of the gas-liquid separator is used to discharge condensed water.

4. The semi-closed power generation cycle system according to claim 3, characterized in that: The circulation component further includes a precooler and a pressure stabilizing tank connected in series between the gas-liquid separator and the compressor; The inlet and outlet of the precooler are respectively communicated with the gas outlet of the gas-liquid separator and the inlet of the surge tank, and the first outlet of the surge tank is communicated with the inlet of the compressor.

5. The semi-closed power generation cycle system according to claim 4, characterized in that: The motor and the compressor are linked via a coupling, and the second outlet of the surge tank is used to discharge gas for gas capture.

6. The semi-closed power generation cycle system according to claim 5, characterized in that: The first outlet and the second outlet are located at the top and the bottom of the surge tank, respectively.

7. The semi-closed power generation cycle system according to any one of claims 1 to 6, characterized in that: The flue gas outlet of the burner is connected to the inlet of the gas turbine via a first pipe, and the flue gas outlet of the burner is connected to the hot side inlet of the regenerator via a second pipe; The first regulating valve is connected in series to the first pipeline, and the second regulating valve is connected in series to the second pipeline.

8. The semi-closed power generation cycle system according to claim 7, characterized in that: The valve nominal diameter of the second regulating valve is half of the valve nominal diameter of the first regulating valve, and the pipe nominal diameter of the second pipeline is half of the pipe nominal diameter of the first pipeline.

9. An isothermal load-changing method for a semi-closed power generation cycle system, characterized in that: Using the semi-closed power generation cycle system according to any one of claims 1 to 8, the method comprises: When the load needs to be reduced, the first regulating valve is closed and the second regulating valve is opened synchronously; when the load needs to be increased, the first regulating valve is opened and the second regulating valve is closed synchronously; wherein, When the first regulating valve is in a fully open state and the second regulating valve is in a fully closed state, the semi-closed power generation cycle system is in a full-load operating state.

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